Rough idle and a steady misfire

I have a 2000 Toyota Avalon XLS with 134k miles, engine is a v6 (3.0). It has a rough idle and a steady misfire. You can drive it sometimes and it will run perfect and you can drive it sometimes and it will misfire. I am getting codes P1150, P0300,P0302, P0304,P0306. Driving me nuts. Any ides?

when wasw the last time you replaced the spark plugs?